Commit c3d8e0b5 authored by Xiubo Li's avatar Xiubo Li Committed by Ilya Dryomov
Browse files

ceph: return the real size read when it hits EOF 



Currently, if the sync read handler ends up reading more from the last
object in the file than the i_size indicates, then it'll end up
returning the wrong length. Ensure that we cap the returned length and
pos at the EOF.

Signed-off-by: default avatarXiubo Li <xiubli@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 8cfc0c7e

fs/ceph/file.c

+8 −5
Original line number Diff line number Diff line
@@ -847,6 +847,7 @@ static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *to, 
	ssize_t ret;

	u64 off = iocb->ki_pos;

	u64 len = iov_iter_count(to);

	u64 i_size;



	dout("sync_read on file %p %llu~%u %s\n", file, off, (unsigned)len,

	     (file->f_flags & O_DIRECT) ? "O_DIRECT" : "");
@@ -870,7 +871,6 @@ static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *to, 
		struct page **pages;

		int num_pages;

		size_t page_off;

		u64 i_size;

		bool more;

		int idx;

		size_t left;
@@ -953,12 +953,15 @@ static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *to, 
	}



	if (off > iocb->ki_pos) {

		if (ret >= 0 &&

		    iov_iter_count(to) > 0 && off >= i_size_read(inode))

		if (off >= i_size) {

			*retry_op = CHECK_EOF;

			ret = i_size - iocb->ki_pos;

			iocb->ki_pos = i_size;

		} else {

			ret = off - iocb->ki_pos;

			iocb->ki_pos = off;

		}

	}



	dout("sync_read result %zd retry_op %d\n", ret, *retry_op);

	return ret;